Automatic fire alarm



Feb. 22 1927.

- I c. c. BETTENHAUSEN AUTOMATIC FIRE ALARM Filed June 30, B25

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C C BETT' NHAUS &

ATTORNEY' 15' alarm.

Patented Feb. 22, 1927.

| ;:em-e 1 Sam:- ES

, CHARLES C. BEr'rEm-IAUsEN, or PRINCETON, NEBRASKA.

AUTOMATIC FIRE ALARM.

Application filed June so, 1925. Serial No. 40,601.

My invention relates to automatic fire alarmsand particularly to the type of fire alarins' which are designed to give warning 7' 6f overheated bearings. The object of my '5 invention is the-provision of a me alarm I adapted to quickly and easily ap lied-to bearings of any and all types, 7 which is reliable in action, which is simple 1 in construction and which can be made and i soldat a rel atively low figure. Other objects will be' brought out in the following I description.

" Referring nowto the'drawings,

Figure 1- isa' view in perspective of the fire Figureais a plan View of the bottom side ofthe'fir amr 1 Figure; )3 is a plan view looking down upon the fir'eialar'm, the cover of the case 20 being removedto disclose the contact arranement; r

Ingure 4 is a median vertical sectional viewshowing the operative mechanism of the fire'alarm.

25. Figure 5i's-a plan view showing how the 'fir'e' alarmmay be secured toa bearing havihg aco'nve'x surface.

' Figure 6 is a similar view showing the application of the alarm to'a sunken be'ar- Tigure 7 isa plan View of the cap and of the portion of the body member, showing therlation of the capto one of the binding posts. V

FigureS a view showing the details of one of the binding posts and the contact member.

The body member 10 is in the form of an elongated cylinder having a closed top 11. Spaced slightly from the lower open end of the body member is the horizontal support 12. The shaft 13 is positioned cen- I i trally in the body member 10 and has its bearings in the top 11 and in the support 12. The thermostatic member 14, which" in the resent instance is in the form'of a coil spring, is firmly secured to the shaft 13 and loosely secured to a pin 15 projecting from the support 12. The thermostatic member 14 surrounds the shaft 13 and is slightly spaced from the support 12. It is preferably placed on the under side of the support so as to position it as closely as possible to the hearing, as it is desirable to space the thermostatic member from its support in order to prevent binding. At the upper extremity of the shaft 13 is a pointer 16 which is secured soas" to rotate with the shaft. The pointer may be securedto the shaft in a manner common with clock hands and is preferably held in'position by means of a nut 17 on the upper end of the shaft. It will be observed that as changes in temperature affect the thermostatic member, the shaft 13 and the pointer 16' willfbe' ro- ,tatedL At one side of the body member 10 is an upwardly projecting stri 18 which'ser'ves as a support for the binding post 19. This binding post must be completely insulated from the strip 18 by means of suitable insulating washers on the two sides and within the strip. On its inner end thebinding post 19 is provided with a conducting eX- tension having therein a contact screw 20 as shown in Figure 8. The construction is such that a rise in temperature will cause the pointer 16 to move toward the contact screw 20. The contact screw 20 thus pro vides a means for adjusting the parts for any desired p'redetern'iined maximum temperature.

In order to protect the contact parts from injury as well as fron chaff and other foreign matter th cap'2l serves as a cover. The Y cover 21 is the usual slip cover but it is pro vided with a pair of notches for clearing the binding posts 19 and 22; It is important, however, that the cover be prevcnted from coming into Contact with thebiinding post 19 and thus rendering the signal inoperative through a short circuit. The notch for the binding post 19 is therefore made amply large for clearing the binding post but the notch engaging the binding post 22 is only sufliciently large to pass over the post, as shown in Figure 7. It is therefore impossible through carelessness or accident to apply the cap 21 in such a way as to short circuit the lire alarm.

The great difficulty with fire alarm devices of this kind has been the problem of applying the devices efi'ectively to the bearings. In some kinds this has been done by drilling holes into the bearings, while in other cases the alarm mechanism has been so loosely attached that the vibration of the shaft would eventually ar it loose. The securing -1neans which I employ comprises a clamping member 26 having a base 27, the two parts having been formed either from a single piece of sheet metal or from two pieces which.

(ill

are united by welding or soldering. The collar portion 26 is just sufliciently large to permit" the body member 10 to slide freely therein. This collar member may, however,

i be tightened against the body member 10 at the part 27 such as may be necessary for adapting the device to some types of bearings.

In use, the clamping member is secured to the journal boX or other suitable support.

near the bearing, the base 27 being bendable into any desired form to conform to the shap of the support. The clamping member may be secured to its support by means of bolts or screws as suggested in Figure 5. The body member 10 isfitted to the bearing by cutting out segments from its lower edge so as to position the thermostatic member as closely as possible to the bearing. The body member is then thrust down through the clamping member until its lower edge is in intimate contact with the bearing, after which it is firmly secured in position by tightening the screws or bolts 28. Lastly an electrical circuit is established through the binding posts 19 and 22 and through a bell, pilot light or other suitable signal or alarm.

The signal device as above described was designed primarily to meet the need for a fire alarm in mills and elevators. The bearings in these places, frequently overheat and require constant inspection to prevent disastrous fires. These bearings are however of difficult access and the result is that much is left to chance. Such structures are often consumed by fire and the insurance rates are necessarily high because of the fire hazard. With my device this hazard may be all but eliminated at an almost insignificant cost. The installation is a simple matter, so

terms which will be readily understood by others skilled in the art to which it pertains, what I claim as new and desire to secure by Letters Patent of the United States is:

A casing which is adapted to receive a. thermal switch, and means for securing said casing in contact with a bearing, said casing being elongated and tubular and being open at its contact end and closed at its opposite end, a slip cover for the closed end of said casing, stops on said casing for limiting the inward movement of said slip cover to'thereby form a chamber between the closed end of said casing and said slip cover for receiving a switch mechanism, said securing means comprising a flexible base which is adapted to be secured to a suitable support in proximity to the bearing and a circular collar secured to said base, said collar being in the form of two semicircular parts with radially projecting ears at their extremities and being adapted to slidably receive said casing whereby said casing may be adjusted into intimate contact with the bearing, each pair of said ears being provided with registering apertures for the reception of a bolt for drawing together the two parts of the collar to thereby clamp the said casing in said collar in any desired position of adjustment.

In witness whereof I afiix my signature.

CHARLES C. BETTENHAUSEN. 

